In general, a pipe of a beer drawing device is connected to a completely sealed beer barrel and a cock valve provided in the beer drawing device is manipulated before draft beer is provided to the consumer in a beer glass. Sometimes, a cooling device is further attached to the pipe of the beer drawing device as necessary.
However, when beer in a beer barrel flows out through the beer drawing device, beer stones are deposited in the pipe or on the inside of the beer drawing device.
Such beer stones become causes of deteriorating the beer to spoil its taste and contaminating the beer. Conventionally, chemicals were injected or wash water was pressure-injected to remove the beer stones, but not only is there a decrease in the beer stone removal efficiency over time but also there is a problem that most beer stone removing chemicals should not be ingested by humans.
Meanwhile, when the beer drawing device is first opened to receive the first glass of beer after the beer barrel is connected to the beer drawing device, beer spurts out bubbling with a noise of “pung” due to carbon dioxide gas fed from the beer barrel. Such a phenomenon is called a beer spurting phenomenon induced by gas. Such a phenomenon occurs not only when the first glass of beer is filled but also when the last glass of beer is filled from the beer barrel. This is because carbon dioxide gas is discharged out of the beer drawing device together with beer remaining in the beer barrel.
Such a gas spurting phenomenon is not only very bothersome to the user but also it is not good hygienically as spurting draft beer spatters in all directions.
To prevent such a gas spurting phenomenon, the beer and carbon dioxide gas that were in the beer drawing device and the pipe should be artificially discharged, with the beer barrel and the beer drawing device being separated from each other, when exchanging the beer barrel.
However, a considerable quantity of draft beer is lost in the process of discharging the remaining beer and carbon dioxide gas, and not only much time is required for exchanging the beer barrel, but also there is a problem that the beer barrel exchange work is very cumbersome.